new season ticket holders

ive been saving up on and off since july last year when ive finally got back into work after 2 years out with no luck and injuries, i understand the whole current season ticket holders got a date to renew thier currents seats,
i was wondering if any current season ticket holder can help me understand how to purchase one,
are there certain dates that you got till you can purchase one? ive heard you can do it by direct debit which would suite me down to the ground will even consider getting misses one aswell.
any info will be brilliant, i was planning on ringing down in next few weeks but they never answer thier bloody phones

Ive always bought mine online. Its pretty straight forward.